[Carry_Okie]

Yup, all three, supposedly, though without a store of value there is no unit of account. The collateral is the total wealth of the United States, its land, mineral estate, human capital. They don't tell you about that part, but that's why ther Federill Grubbamint keeps stealing wealth from its owners (besides for the fun and profit of its agencies, the manipulation of its political sponsors...). That's where the system is crooked and another reason why I think private monetary systems may be the only way to buy back our liberty. It's going the other way right now.

[Mikey]

"...I think private monetary systems may be the only way to buy back our liberty..."

The Federal reserve is a private for profit corporation.
No, the only way to get outta this mess is to return to the original document that spelled it all out, the Constitution for the United States.

Article 1, Section 10, clause 1 "No state shall...make anything but gold and silver coin a tender in payment of debts..."

See also Article 1, sec 8, clause 5